The U.S. Navy warship USS Lassen was warned and trailed by Chinese ships and aircraft as it came within 12 nautical miles of the islands in the South China Sea. The ship sailed near the Spratly Islands, which are composed of man-made islands above coral reefs. These islands were dredging operations by the Chinese in 2014; the Chinese consider the islands to be Chinese territory. The U.S. Defense Secretary stated that the U.S. will operate wherever international law allows, especially if such actions meet the needs of the U.S. The Chinese government has responded by warning that foreign countries should not try to create tension or cause trouble with China, for China will engage in legal activities to enforce its laws. The contested waters of the South China Sea are a large issue in relation to international maritime laws. The South China Sea and its islands have been claimed by many Southeast Asian countries such as Vietnam, Taiwan, and the Philippines. Other nations support the idea of an open sea to all nations so that it can be considered international waters. Because maritime law does not state that artificial islands are given the 12-mile territorial zone, the U.S. deliberately sent its ship for this reason. Chinese President Xi Jinping’s recent trip to Washington had made little progress on the issue of the South China Sea.